A sliding type cell phone generally has a telescopic mechanism and includes a first housing and a second housing coupled to each other slidably on a rail part. The cell phone advantageously includes a large display screen on the first housing and a key operation part on the second housing thus allowing key operation while browsing the large screen in an elongated state. Moreover, in a contracted state, the key operation part is housed in the cell phone thus preventing operation errors and allowing the cell phone to be carried along in a compact shape.
As an antenna used for such a sliding type portable wireless device, a helical antenna or a telescopic antenna is known (for example, refer to Patent Reference 1).
Patent Reference 1: JP-A-2003-309631 (Page 5, FIGS. 1 to 4)